This invention relates in general to electronic devices and in particular to electronic devices arranged as an automatic control system for vehicles.
Automatic vehicular control systems represent an attempt by man to simplify a manual activity by the use of electronics. A variety of automotive electronic systems have been utilized in the past, such as systems for controlling ignition timing and fuel injection as functions of various engine parameters, and automatic starting systems.
Various remote-control engine starting systems for automobiles and other vehicles have been proposed. U.S. Pat. No. 4,200,080, issued Apr. 29, 1980 to myself and William Kirby as joint inventors, discloses an automatic starting system which includes a settable clock device in parallel with a remote-control receiver, a plurality of relays and timed thermal switches, a thermal switch flasher and solenoid coupled to the throttle-gas pedal linkage of the vehicle. Means are provided for pumping the vehicle gas pedal prior to coupling current to the starter, according to vehicle manufacturers' recommendations for starting most vehicles which have a cold engine. A number of safety features such as a hood safety switch, an overspeed switch, a temperature switch and a low oil pressure switch are provided in order to prevent damage to the vehicle and to prevent injury to others. The system includes means responsive to engine vacuum level for coupling battery power to vehicle accessory items such as an air conditioner or heater after the engine starts.
Other circuit arrangements which have been conceived in an attempt to provide improvements to automatic starting systems are disclosed in the following patents and publications:
______________________________________ U.S. Pat. No. Patentee Issue Date ______________________________________ 2,698,391 Braden et al. Dec. 28, 1954 2,748,759 Schiffer June 5, 1956 2,836,732 Newlin May 27, 1958 2,975,296 Dominguez-Rego March 14, 1961 3,530,846 Bean et al. Sept. 29, 1970 3,538,898 Egdemir Nov. 10, 1970 3,696,333 Mott Oct. 3, 1972 3,859,540 Weiner Jan. 7, 1975 4,080,537 Bucher Mar. 21, 1978 4,236,594 Ramsperger Dec. 2, 1980 4,345,554 Hildreth et al. Aug. 24, 1982 4,392,059 Nespor July 5, 1983 4,446,460 Tholl et al. May 1, 1984 ______________________________________ Publications: Advertisement, TranStart, Inc., USAir Magazine, December, 1984, p. 21.: Owner's Manual, TranStart, Inc. Remote Starter Model GS1000
Braden et al. discloses an engine-control system whereby an engine may be started and stopped automatically under the control of a clock mechanism. Also provided are means to start and stop the engine under certain temperature conditions.
Schiffer discloses an automatic starting device for an internal combustion engine which incorporates a timing mechanism for starting a car at a speed somewhat above idling speed and reducing the speed to the correct idling speed when the proper vehicle temperature is reached.
Newlin discloses an automatic car starter for automatically starting a motor vehicle at a predetermined time and energizing the motor vehicle heater at the predetermined time, whereby the automobile engine and the interior of the automobile will have had sufficient time to warm up when the operator enters the vehicle.
Dominguez-Rego discloses a clock-control circuit for energizing the ignition circuit of a vehicle, the starter and the heater and for controlling the throttle opening during the starting and warm-up periods. The circuit deenergizes the starter once the engine has started and restarts the engine if it stalls while warming up or idling.
Mott discloses an automatic automobile starter which permits utilization of either a clock-switching mechanism or a radio remote control switching system to supply current to the starter motor. Current is supplied to the ignition coil through an oil pressure switch to insure that the engine will not start unless there is sufficient oil pressure.
Bucher discloses a remote starting system for an internal combustion engine which enables the user to start the engine from a remote location using a receiver for receiving a command signal from a remote transmitter operated by the user. Provision is made for shutting down the system immediately upon any tampering with the vehicle such as by depression of the brake pedal or opening a door.
Egdemir discloses an automatic presettable car starting system for warming up the car any time during a 24-hour period by presetting the clock device. This system includes a mechanism for depressing the gas pedal a selected number of times during the cycle.
The patent to Nespor discloses a radio-controlled automatic remote car starter in which a single initial signal from the transmitter initiates an automatic engine starting and warm-up sequence which includes providing fuel to the engine, providing power to the starter, providing power to the vehicle heater and ignition, and, upon the engine reaching operating temperature and the interior of the vehicle consequently becoming heated, removing power from the ignition and heater.
Hildreth et al. disclose a remotely controlled engine starter and protective system in which an accessories timer is provided to delay energization of the heater and air conditioner for 30 seconds in order to reduce the electrical load on the battery while starting.
Weiner discloses a system for remote control of an automobile engine including visual indication of accelerator linkage and starter circuit actuation.
Bean et al. describe remote engine starting using a modulated RF carrier signal in the Citizen's Band.
Tholl et al. describe a simplified apparatus for remotely starting an internal combustion engine employing silicon-controlled rectifiers (SCRs) to switch power to the starter relay, solenoid, accessories and ignition of a vehicle. This system employs a predetermined set of coded signals.
Automatic starting systems such as those illustrated above provide significant benefits in terms of both convenience and time savings, enabling a driver to remotely start a vehicle engine so as to allow it to warm up while he continues to dress, eat or otherwise prepare for departure. Electronic systems have been used to advantage in other automotive application as well, such as engine monitoring and control, as previously stated. However, there remains a need for an automotive security system capable of adequately protecting an operator in the event explosives are wired to an electrical system component of the vehicle. Although various automotive electronic systems have been available for some time, it has not heretofore been recognized that an electronic system could offer adequate security against explosives, and as a result extremely dangerous manual bomb detection methods are still routinely employed. All the above-described remote starting systems cannot provide such security. A bomb can be electrically connected to a vehicle's headlights, horn or other electrical component where it cannot be detected merely by remotely starting the engine.
A remote starter manufactured by TranStart, Inc., featured in the above-referenced advertisement in USAir Magazine and described in detail in the above-referenced owner's manual, can automatically start a car and, through a relay, activate selected auxiliary systems such as the car's heater, defroster, air conditioner and radio. A toggle switch is provided for control of vehicle lights. As described on page 8 of the owner's manual, one terminal of this switch is connected to the relay output, and the other terminal is connected to the headlight low beam and, if desired, the parking light. As noted below the wiring diagram for the toggle switch, connecting the parking lights with the headlights causes the headlights to be activated when the parking light switch is on. Not only does the driver lose independent control of headlights and parking lights by this connection, but turning the parking light switch on causes the parking light wiring to draw headlight-level current, in excess of design specifications for that wiring. No provision is made for activating the vehicle's bright headlights. In fact, the switch installation instructions contain a note to be sure not to connect the wire for the headlights to the brights. Further, this system leaves all activated auxiliary systems on as long as the system itself stays on, thereby unnecessarily draining power from the charging system of the car and possibly causing a poorly idling car to stall.
One system for automatically controlling automotive starting and accessory functions, such as raising and lowering windows, controlling door locks and trunk lock, air conditioning system, heating system, headlights and radio antenna is known, and is described in the patent to Ramsperger. This system employs a remote keyboard and encoder coupled via a radio link to a microprocessor inside the vehicle, and includes particular key assignments for particular accessories. Although this system could conceivably provide some measure of safety by enabling an operator to remotely actuate a selected device, this system has several attributes making it inadequate for security use. First, individual accessories are actuated by separately depressing corresponding keys on the keyboard. An operator could not check all the controllable system components without manually stepping through all possible commands, a procedure which is subject to operator error, especially considering the number of available commands. This risk of operator error is aggravated by the fact that three keys must be depressed in a particular sequence for each desired command. Even assuming that an operator recognized that bomb detection might be possible with this system, this tedious and demanding sequence of operations would likely destroy an operator's confidence in the system. Further, for testing every circuit which can be controlled, a long series of data bits would have to be transmitted, any one bit of which could be received in error, or not received at all, due to interference or signal degradation caused by structural features of the building within which the remote transmitter is used, or other surrounding buildings, as well as by weather and excessive range. A single transmission error could be fatal to a driver who operates the car without recognizing that a selected system component has not been tested. Moreover, after activating every system component for the test, the operator would have to step through another tedious sequence of keystrokes to deactivate components.